Acts12chapter 12

Herod Agrippa I was a grandson of Herod the Great who had grown up in Rome among the imperial family and was handed the whole of his grandfather's kingdom by the emperors he had befriended. He courted Jewish opinion carefully, keeping the Law in public, which is exactly why executing a Christian leader was good politics for him.

James was killed with the sword — beheading, a swifter and more Roman death than stoning. He is the first of the twelve to die, and Luke gives it a single sentence.

Peter is guarded by four squads of four soldiers, one squad per watch of the night, with two men chained to him. Under Roman practice a guard who lost a prisoner faced the prisoner's punishment, which explains the executions ordered when he is found gone.

Agrippa's death at Caesarea is described independently by Josephus, who says the king appeared in a robe of silver that flashed in the morning sun, that flatterers hailed him as a god, and that he was seized with pain and died days later. The Tyre and Sidon delegation in Luke's account came because those coastal cities depended on grain from Agrippa's territory.